Sea-Gull · Sea-Gull ST2130

Sea-Gull Ocean Series and Okeanos power reserve: inside the ST2130

Sea-Gull's Ocean Series dive watches, the 1000 m Okeanos and most of the brand's automatic dress and field watches run on the ST2130, which lasts about 40 hours off the wrist. That's a little under two days, so a Sea-Gull put down on Friday evening will usually have stopped by Sunday morning.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the ST2130

If you own an automatic Sea-Gull with three central hands and a date, the ST2130 is the most likely movement inside. It's the Tianjin maker's everyday automatic, used in its divers, its aviation-style watches and its dress watches for men and women alike. Sea-Gull also sells it as a loose movement, sometimes listed as the TY2130, so it turns up in other brands' watches too. The famous Sea-Gull 1963 chronograph is a different story: it uses the hand-wound ST1901.

Specs at a glance

History and where it came from

Sea-Gull began in 1955 as the Tianjin Watch Factory and is now the Tianjin Seagull Watch Group, which Monochrome describes as the largest producer of mechanical movements in the world, making about a quarter of global output. Its Swiss roots are real: in the 1960s it acquired machinery and designs from the Swiss movement maker Venus, which is where the 1963 chronograph's ST19 movement comes from.

The ST21 family is Sea-Gull's line of 4 Hz automatics. Sea-Gull lists it with close siblings built on the same base, including the ST2100 with a day and date and the ST2108 with a moon phase, all at 28,800 vph, 28 jewels and a 40-hour reserve. The ST2130 is the plain three-hands-and-date member. aBlogtoWatch described it as similar in architecture to the ETA 2824-2, which is a fair shorthand: the same kind of 4 Hz, date-equipped workhorse, sized around 26 mm across.

It has made Sea-Gull a genuine alternative to Japanese and Swiss supply for affordable watches. The Ocean Series divers show where Sea-Gull wants to take it: sapphire bezels, 300 m and 1000 m cases, and even titanium, all around a movement it makes itself.

Accuracy in the real world

Sea-Gull doesn't publish an accuracy tolerance for the ST2130 on its movement or watch pages. Without one, all we can go on is reviews and owners. aBlogtoWatch expected it to "perform nearly as well as most Swiss and Japanese equivalents". Without a factory tolerance, though, expect more variation between examples than you'd get from a regulated Swiss grade.

The 4 Hz beat helps. A faster balance is less upset by knocks and changes in position than the 3 Hz or 2.75 Hz movements found in some rivals at this price, so a well-regulated ST2130 has the potential to hold a steady rate. And like the ETA 2824 it resembles, it has a conventional regulator, so a watchmaker can adjust a fast or slow watch quickly.

If your Sea-Gull suddenly starts running several minutes a day fast, check for magnetism before assuming a fault. That's the usual cause of a sudden change in rate on any affordable movement.

Reliability and servicing

There's no widely reported systemic weakness in the ST2130. It's a simple, conventional automatic, and Sea-Gull's movements have a long track record in watches sold around the world.

• Service or swap. Sea-Gull sells the ST2130 as a complete movement. For an inexpensive watch, replacing the movement can cost less than a full overhaul.
• Parts outside China. Individual parts can be harder to find than for an ETA or Seiko, which is the main servicing drawback. Watchmakers familiar with 2824-style layouts can work on it, but some prefer not to take on Chinese movements.
• Warranty. Sea-Gull lists a two-year warranty on most ST2130 watches (one year on some models).

Quirks worth knowing

• 40 or 42 hours? Sea-Gull's own movement listing says 40 hours, while some of its watch pages and aBlogtoWatch's Okeanos review say 42. Plan around 40.
• It hacks. Sea-Gull lists stop-seconds, so pulling the crown to set the time stops the seconds hand. Not every movement at this price does that.
• Name confusion. The TY2130 and ST2130 are listed together by Sea-Gull. If a listing from another brand says "2130", check whether it names Sea-Gull as the maker.
• Setting the date. As with most date movements, avoid quick-setting the date late in the evening. Here's why.

How it compares

• ETA 2824-2 / Sellita SW200: the Swiss movements it most resembles. Same 4 Hz beat, about 38 hours, more predictable regulation and easier parts supply, at a higher price.
• Seiko NH35: the default for affordable microbrand divers. It hacks and hand-winds too, with about 41 hours, but beats more slowly at 3 Hz.
• Miyota 8215: about 42 hours and 3 Hz, but it doesn't hack, and Monochrome notes a tolerance of -20/+40 s/day.
• Miyota 9015: Citizen's thinner 4 Hz automatic, with about 42 hours. The closest Japanese rival in spec.
• Vostok 2416B: the other big non-Japanese, non-Swiss workhorse. Tougher reputation, but slower, non-hacking and only 31 hours.

Living with the 40-hour reserve

Forty hours covers a normal night with plenty to spare, but not a weekend. Take your Sea-Gull Ocean Series off at 7pm on Friday and, if it was fully wound, it's still running on Saturday evening and stops around 11am on Sunday. Put it on again Monday and you'll be setting the time and date.

Partial winding makes it shorter. A 300 m diver worn for a few quiet hours may go into the drawer carrying only a day's charge, which is how a Sea-Gull ends up stopped on a Saturday morning. If you rotate it with other watches, give it 30 to 40 turns of the crown before putting it away. Watch Winder counts down this 40-hour reserve for each watch you own and reminds you before it stops. To check a specific weekend or trip, try the "Will my watch stop?" calculator.

Verdict

The ST2130 is a competent, conventional 4 Hz automatic that lets Sea-Gull build serious-looking divers and dress watches at modest prices around its own movement. It hacks, it has 28 jewels, and reviewers rate it close to Swiss and Japanese equivalents. The trade-offs are the lack of a published accuracy spec, patchier parts supply outside China, and a reserve of about 40 hours that won't cover a weekend. If you want an Ocean Series or Okeanos diver, the movement is no reason to hesitate. Just wind it before a weekend off.

FAQ

How long does a Sea-Gull Ocean Series watch run off the wrist?

A fully wound Sea-Gull Ocean Series diver with the ST2130 runs for about 40 hours, a little under two days. If it was only partly wound, it will stop sooner.

Does the Sea-Gull ST2130 hack?

Yes. Sea-Gull lists stop-seconds for the ST2130, so the seconds hand stops when you pull the crown to set the time.

What movement is in the Sea-Gull Okeanos?

The Sea-Gull Okeanos 1000 m diver uses the automatic ST2130, a 4 Hz movement with a date, shown at 6 o'clock on that model.

Is the Sea-Gull ST2130 a copy of the ETA 2824?

It's Sea-Gull's own movement, but its layout is similar to the ETA 2824-2, and it shares the 4 Hz beat, central seconds and date. It isn't a parts-compatible clone as far as we could confirm.

How accurate is the Sea-Gull Ocean Series Pro?

Sea-Gull doesn't publish an accuracy figure for the ST2130. Reviewers expect it to perform close to Swiss and Japanese equivalents, and a watchmaker can regulate it with its conventional regulator.

Why did my Sea-Gull stop over the weekend?

With about 40 hours of reserve, a Sea-Gull taken off on Friday evening will normally stop some time on Sunday, even when fully wound. That's expected behaviour, not a fault.

Does the Sea-Gull 1963 use the ST2130?

No. The Sea-Gull 1963 chronograph uses the hand-wound ST1901 column-wheel chronograph movement. The ST2130 is used in Sea-Gull's automatic three-hand watches.

Sources

• Sea-Gull: TY2130/ST2130 movement specifications
• Sea-Gull: Ocean Series Pro 300m 44mm (816.32.1210)
• aBlogtoWatch: Seagull Okeanos Professional Ultra review
• Monochrome: Alternatives to ETA and Sellita, with Seagull, Seiko and Miyota

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 10 hours of wear fills the Sea-Gull ST2130. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 40 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the Sea-Gull ST2130: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.